New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas
International audience Hot spot lavas show a large diversity of isotope compositions resulting from the recycling ofsurface material into the convective mantle. Amongst the mantle end‐members, EM‐1 (enriched mantle)is widely debated and scenarios involving either old pelagic sediments subducted into...
Published in: | Geochemistry, Geophysics, Geosystems |
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Online Access: | https://uca.hal.science/hal-02156044 https://uca.hal.science/hal-02156044/document https://uca.hal.science/hal-02156044/file/Boyet%20etal%20G3%202019.pdf https://doi.org/10.1029/2019GC008228 |
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ftunivstetienne:oai:HAL:hal-02156044v1 2024-06-23T07:56:47+00:00 New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas Boyet, M. Doucelance, R. Israel, C. Bonnand, P. Auclair, Delphine Suchorski, K. Bosq, Chantal Laboratoire Magmas et Volcans (LMV) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS) ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010) ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016) 2019-05-29 https://uca.hal.science/hal-02156044 https://uca.hal.science/hal-02156044/document https://uca.hal.science/hal-02156044/file/Boyet%20etal%20G3%202019.pdf https://doi.org/10.1029/2019GC008228 en eng HAL CCSD AGU and the Geochemical Society info:eu-repo/semantics/altIdentifier/doi/10.1029/2019GC008228 hal-02156044 https://uca.hal.science/hal-02156044 https://uca.hal.science/hal-02156044/document https://uca.hal.science/hal-02156044/file/Boyet%20etal%20G3%202019.pdf doi:10.1029/2019GC008228 info:eu-repo/semantics/OpenAccess ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://uca.hal.science/hal-02156044 Geochemistry, Geophysics, Geosystems, 2019, ⟨10.1029/2019GC008228⟩ [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry info:eu-repo/semantics/article Journal articles 2019 ftunivstetienne https://doi.org/10.1029/2019GC008228 2024-06-11T00:03:29Z International audience Hot spot lavas show a large diversity of isotope compositions resulting from the recycling ofsurface material into the convective mantle. Amongst the mantle end‐members, EM‐1 (enriched mantle)is widely debated and scenarios involving either old pelagic sediments subducted into the deep mantle orsubcontinental lithospheric material incorporated at shallow depths are commonly evoked. We selected 12lavas from Gough Island (south Atlantic Ocean) for the measurement of 138La‐138Ce, 147Sm‐143Nd, and176Lu‐177Hf isotope systems. Results show limited ranges for ε143Nd, ε138Ce, and ε176Hf values, and Ce/Ce*do not correlate with measured isotope ratios. Cerium isotope compositions allow us to exclude thecontribution of old sedimentary material carrying a negative, elemental cerium anomaly in the mantlesource. Pelagic sediments are indeed characterized by strongly negative, elemental cerium anomalies andalso high La/Ce ratios. Modeling a primitive mantle source contaminated by 0.4% to 2.2% of different 2.5Ga‐old pelagic components is able to reproduce the lowest Ce/Ce* values. However, the cerium isotopemeasurements show ε138Ce values between −0.39 and 0.15, too low to give support to the incorporation ofrecycled pelagic sediments in the mantle source of the lavas. Our results suggest that the incorporation ofsubcontinental lithospheric material at shallow depths during the plume ascent is a more suitable modelto explain the formation of the EM‐1 component. Hafnium and Nd isotopes also support this scenario.Subcontinental lithosphere sampled via kimberlites and lamproites has isotopic compositions that plotgenerally below the mantle array, a signature that is also seen in Gough lavas. Article in Journal/Newspaper South Atlantic Ocean Université Jean Monnet – Saint-Etienne: HAL Gough ENVELOPE(159.367,159.367,-81.633,-81.633) Geochemistry, Geophysics, Geosystems |
institution |
Open Polar |
collection |
Université Jean Monnet – Saint-Etienne: HAL |
op_collection_id |
ftunivstetienne |
language |
English |
topic |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
spellingShingle |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Boyet, M. Doucelance, R. Israel, C. Bonnand, P. Auclair, Delphine Suchorski, K. Bosq, Chantal New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas |
topic_facet |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
description |
International audience Hot spot lavas show a large diversity of isotope compositions resulting from the recycling ofsurface material into the convective mantle. Amongst the mantle end‐members, EM‐1 (enriched mantle)is widely debated and scenarios involving either old pelagic sediments subducted into the deep mantle orsubcontinental lithospheric material incorporated at shallow depths are commonly evoked. We selected 12lavas from Gough Island (south Atlantic Ocean) for the measurement of 138La‐138Ce, 147Sm‐143Nd, and176Lu‐177Hf isotope systems. Results show limited ranges for ε143Nd, ε138Ce, and ε176Hf values, and Ce/Ce*do not correlate with measured isotope ratios. Cerium isotope compositions allow us to exclude thecontribution of old sedimentary material carrying a negative, elemental cerium anomaly in the mantlesource. Pelagic sediments are indeed characterized by strongly negative, elemental cerium anomalies andalso high La/Ce ratios. Modeling a primitive mantle source contaminated by 0.4% to 2.2% of different 2.5Ga‐old pelagic components is able to reproduce the lowest Ce/Ce* values. However, the cerium isotopemeasurements show ε138Ce values between −0.39 and 0.15, too low to give support to the incorporation ofrecycled pelagic sediments in the mantle source of the lavas. Our results suggest that the incorporation ofsubcontinental lithospheric material at shallow depths during the plume ascent is a more suitable modelto explain the formation of the EM‐1 component. Hafnium and Nd isotopes also support this scenario.Subcontinental lithosphere sampled via kimberlites and lamproites has isotopic compositions that plotgenerally below the mantle array, a signature that is also seen in Gough lavas. |
author2 |
Laboratoire Magmas et Volcans (LMV) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS) ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010) ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016) |
format |
Article in Journal/Newspaper |
author |
Boyet, M. Doucelance, R. Israel, C. Bonnand, P. Auclair, Delphine Suchorski, K. Bosq, Chantal |
author_facet |
Boyet, M. Doucelance, R. Israel, C. Bonnand, P. Auclair, Delphine Suchorski, K. Bosq, Chantal |
author_sort |
Boyet, M. |
title |
New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas |
title_short |
New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas |
title_full |
New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas |
title_fullStr |
New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas |
title_full_unstemmed |
New Constraints on the Origin of the EM‐1 Component Revealed by the Measurement of the La‐Ce Isotope Systematics in Gough Island Lavas |
title_sort |
new constraints on the origin of the em‐1 component revealed by the measurement of the la‐ce isotope systematics in gough island lavas |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://uca.hal.science/hal-02156044 https://uca.hal.science/hal-02156044/document https://uca.hal.science/hal-02156044/file/Boyet%20etal%20G3%202019.pdf https://doi.org/10.1029/2019GC008228 |
long_lat |
ENVELOPE(159.367,159.367,-81.633,-81.633) |
geographic |
Gough |
geographic_facet |
Gough |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://uca.hal.science/hal-02156044 Geochemistry, Geophysics, Geosystems, 2019, ⟨10.1029/2019GC008228⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2019GC008228 hal-02156044 https://uca.hal.science/hal-02156044 https://uca.hal.science/hal-02156044/document https://uca.hal.science/hal-02156044/file/Boyet%20etal%20G3%202019.pdf doi:10.1029/2019GC008228 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2019GC008228 |
container_title |
Geochemistry, Geophysics, Geosystems |
_version_ |
1802650128558850048 |